1 /* 2 * 3 * Intel Management Engine Interface (Intel MEI) Linux driver 4 * Copyright (c) 2003-2012, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 */ 16 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/kernel.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/fs.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/fcntl.h> 25 #include <linux/poll.h> 26 #include <linux/init.h> 27 #include <linux/ioctl.h> 28 #include <linux/cdev.h> 29 #include <linux/sched.h> 30 #include <linux/uuid.h> 31 #include <linux/compat.h> 32 #include <linux/jiffies.h> 33 #include <linux/interrupt.h> 34 35 #include <linux/mei.h> 36 37 #include "mei_dev.h" 38 #include "client.h" 39 40 /** 41 * mei_open - the open function 42 * 43 * @inode: pointer to inode structure 44 * @file: pointer to file structure 45 * 46 * Return: 0 on success, <0 on error 47 */ 48 static int mei_open(struct inode *inode, struct file *file) 49 { 50 struct mei_device *dev; 51 struct mei_cl *cl; 52 53 int err; 54 55 dev = container_of(inode->i_cdev, struct mei_device, cdev); 56 if (!dev) 57 return -ENODEV; 58 59 mutex_lock(&dev->device_lock); 60 61 if (dev->dev_state != MEI_DEV_ENABLED) { 62 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n", 63 mei_dev_state_str(dev->dev_state)); 64 err = -ENODEV; 65 goto err_unlock; 66 } 67 68 cl = mei_cl_alloc_linked(dev, MEI_HOST_CLIENT_ID_ANY); 69 if (IS_ERR(cl)) { 70 err = PTR_ERR(cl); 71 goto err_unlock; 72 } 73 74 file->private_data = cl; 75 76 mutex_unlock(&dev->device_lock); 77 78 return nonseekable_open(inode, file); 79 80 err_unlock: 81 mutex_unlock(&dev->device_lock); 82 return err; 83 } 84 85 /** 86 * mei_release - the release function 87 * 88 * @inode: pointer to inode structure 89 * @file: pointer to file structure 90 * 91 * Return: 0 on success, <0 on error 92 */ 93 static int mei_release(struct inode *inode, struct file *file) 94 { 95 struct mei_cl *cl = file->private_data; 96 struct mei_device *dev; 97 int rets = 0; 98 99 if (WARN_ON(!cl || !cl->dev)) 100 return -ENODEV; 101 102 dev = cl->dev; 103 104 mutex_lock(&dev->device_lock); 105 if (cl == &dev->iamthif_cl) { 106 rets = mei_amthif_release(dev, file); 107 goto out; 108 } 109 if (mei_cl_is_connected(cl)) { 110 cl->state = MEI_FILE_DISCONNECTING; 111 cl_dbg(dev, cl, "disconnecting\n"); 112 rets = mei_cl_disconnect(cl); 113 } 114 mei_cl_flush_queues(cl, file); 115 cl_dbg(dev, cl, "removing\n"); 116 117 mei_cl_unlink(cl); 118 119 file->private_data = NULL; 120 121 kfree(cl); 122 out: 123 mutex_unlock(&dev->device_lock); 124 return rets; 125 } 126 127 128 /** 129 * mei_read - the read function. 130 * 131 * @file: pointer to file structure 132 * @ubuf: pointer to user buffer 133 * @length: buffer length 134 * @offset: data offset in buffer 135 * 136 * Return: >=0 data length on success , <0 on error 137 */ 138 static ssize_t mei_read(struct file *file, char __user *ubuf, 139 size_t length, loff_t *offset) 140 { 141 struct mei_cl *cl = file->private_data; 142 struct mei_device *dev; 143 struct mei_cl_cb *cb = NULL; 144 int rets; 145 int err; 146 147 148 if (WARN_ON(!cl || !cl->dev)) 149 return -ENODEV; 150 151 dev = cl->dev; 152 153 154 mutex_lock(&dev->device_lock); 155 if (dev->dev_state != MEI_DEV_ENABLED) { 156 rets = -ENODEV; 157 goto out; 158 } 159 160 if (length == 0) { 161 rets = 0; 162 goto out; 163 } 164 165 if (cl == &dev->iamthif_cl) { 166 rets = mei_amthif_read(dev, file, ubuf, length, offset); 167 goto out; 168 } 169 170 cb = mei_cl_read_cb(cl, file); 171 if (cb) { 172 /* read what left */ 173 if (cb->buf_idx > *offset) 174 goto copy_buffer; 175 /* offset is beyond buf_idx we have no more data return 0 */ 176 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) { 177 rets = 0; 178 goto free; 179 } 180 /* Offset needs to be cleaned for contiguous reads*/ 181 if (cb->buf_idx == 0 && *offset > 0) 182 *offset = 0; 183 } else if (*offset > 0) { 184 *offset = 0; 185 } 186 187 err = mei_cl_read_start(cl, length, file); 188 if (err && err != -EBUSY) { 189 dev_dbg(dev->dev, 190 "mei start read failure with status = %d\n", err); 191 rets = err; 192 goto out; 193 } 194 195 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) { 196 if (file->f_flags & O_NONBLOCK) { 197 rets = -EAGAIN; 198 goto out; 199 } 200 201 mutex_unlock(&dev->device_lock); 202 203 if (wait_event_interruptible(cl->rx_wait, 204 (!list_empty(&cl->rd_completed)) || 205 (!mei_cl_is_connected(cl)))) { 206 207 if (signal_pending(current)) 208 return -EINTR; 209 return -ERESTARTSYS; 210 } 211 212 mutex_lock(&dev->device_lock); 213 if (!mei_cl_is_connected(cl)) { 214 rets = -EBUSY; 215 goto out; 216 } 217 } 218 219 cb = mei_cl_read_cb(cl, file); 220 if (!cb) { 221 rets = 0; 222 goto out; 223 } 224 225 copy_buffer: 226 /* now copy the data to user space */ 227 if (cb->status) { 228 rets = cb->status; 229 dev_dbg(dev->dev, "read operation failed %d\n", rets); 230 goto free; 231 } 232 233 dev_dbg(dev->dev, "buf.size = %d buf.idx= %ld\n", 234 cb->buf.size, cb->buf_idx); 235 if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) { 236 rets = -EMSGSIZE; 237 goto free; 238 } 239 240 /* length is being truncated to PAGE_SIZE, 241 * however buf_idx may point beyond that */ 242 length = min_t(size_t, length, cb->buf_idx - *offset); 243 244 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) { 245 dev_dbg(dev->dev, "failed to copy data to userland\n"); 246 rets = -EFAULT; 247 goto free; 248 } 249 250 rets = length; 251 *offset += length; 252 if ((unsigned long)*offset < cb->buf_idx) 253 goto out; 254 255 free: 256 mei_io_cb_free(cb); 257 258 out: 259 dev_dbg(dev->dev, "end mei read rets= %d\n", rets); 260 mutex_unlock(&dev->device_lock); 261 return rets; 262 } 263 /** 264 * mei_write - the write function. 265 * 266 * @file: pointer to file structure 267 * @ubuf: pointer to user buffer 268 * @length: buffer length 269 * @offset: data offset in buffer 270 * 271 * Return: >=0 data length on success , <0 on error 272 */ 273 static ssize_t mei_write(struct file *file, const char __user *ubuf, 274 size_t length, loff_t *offset) 275 { 276 struct mei_cl *cl = file->private_data; 277 struct mei_me_client *me_cl = NULL; 278 struct mei_cl_cb *write_cb = NULL; 279 struct mei_device *dev; 280 unsigned long timeout = 0; 281 int rets; 282 283 if (WARN_ON(!cl || !cl->dev)) 284 return -ENODEV; 285 286 dev = cl->dev; 287 288 mutex_lock(&dev->device_lock); 289 290 if (dev->dev_state != MEI_DEV_ENABLED) { 291 rets = -ENODEV; 292 goto out; 293 } 294 295 me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id); 296 if (!me_cl) { 297 rets = -ENOTTY; 298 goto out; 299 } 300 301 if (length == 0) { 302 rets = 0; 303 goto out; 304 } 305 306 if (length > me_cl->props.max_msg_length) { 307 rets = -EFBIG; 308 goto out; 309 } 310 311 if (!mei_cl_is_connected(cl)) { 312 cl_err(dev, cl, "is not connected"); 313 rets = -ENODEV; 314 goto out; 315 } 316 if (cl == &dev->iamthif_cl) { 317 write_cb = mei_amthif_find_read_list_entry(dev, file); 318 319 if (write_cb) { 320 timeout = write_cb->read_time + 321 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER); 322 323 if (time_after(jiffies, timeout)) { 324 *offset = 0; 325 mei_io_cb_free(write_cb); 326 write_cb = NULL; 327 } 328 } 329 } 330 331 *offset = 0; 332 write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file); 333 if (!write_cb) { 334 rets = -ENOMEM; 335 goto out; 336 } 337 338 rets = copy_from_user(write_cb->buf.data, ubuf, length); 339 if (rets) { 340 dev_dbg(dev->dev, "failed to copy data from userland\n"); 341 rets = -EFAULT; 342 goto out; 343 } 344 345 if (cl == &dev->iamthif_cl) { 346 rets = mei_amthif_write(cl, write_cb); 347 348 if (rets) { 349 dev_err(dev->dev, 350 "amthif write failed with status = %d\n", rets); 351 goto out; 352 } 353 mei_me_cl_put(me_cl); 354 mutex_unlock(&dev->device_lock); 355 return length; 356 } 357 358 rets = mei_cl_write(cl, write_cb, false); 359 out: 360 mei_me_cl_put(me_cl); 361 mutex_unlock(&dev->device_lock); 362 if (rets < 0) 363 mei_io_cb_free(write_cb); 364 return rets; 365 } 366 367 /** 368 * mei_ioctl_connect_client - the connect to fw client IOCTL function 369 * 370 * @file: private data of the file object 371 * @data: IOCTL connect data, input and output parameters 372 * 373 * Locking: called under "dev->device_lock" lock 374 * 375 * Return: 0 on success, <0 on failure. 376 */ 377 static int mei_ioctl_connect_client(struct file *file, 378 struct mei_connect_client_data *data) 379 { 380 struct mei_device *dev; 381 struct mei_client *client; 382 struct mei_me_client *me_cl; 383 struct mei_cl *cl; 384 int rets; 385 386 cl = file->private_data; 387 dev = cl->dev; 388 389 if (dev->dev_state != MEI_DEV_ENABLED) 390 return -ENODEV; 391 392 if (cl->state != MEI_FILE_INITIALIZING && 393 cl->state != MEI_FILE_DISCONNECTED) 394 return -EBUSY; 395 396 /* find ME client we're trying to connect to */ 397 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid); 398 if (!me_cl || me_cl->props.fixed_address) { 399 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n", 400 &data->in_client_uuid); 401 return -ENOTTY; 402 } 403 404 cl->me_client_id = me_cl->client_id; 405 cl->cl_uuid = me_cl->props.protocol_name; 406 407 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n", 408 cl->me_client_id); 409 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n", 410 me_cl->props.protocol_version); 411 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n", 412 me_cl->props.max_msg_length); 413 414 /* if we're connecting to amthif client then we will use the 415 * existing connection 416 */ 417 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) { 418 dev_dbg(dev->dev, "FW Client is amthi\n"); 419 if (!mei_cl_is_connected(&dev->iamthif_cl)) { 420 rets = -ENODEV; 421 goto end; 422 } 423 mei_cl_unlink(cl); 424 425 kfree(cl); 426 cl = NULL; 427 dev->iamthif_open_count++; 428 file->private_data = &dev->iamthif_cl; 429 430 client = &data->out_client_properties; 431 client->max_msg_length = me_cl->props.max_msg_length; 432 client->protocol_version = me_cl->props.protocol_version; 433 rets = dev->iamthif_cl.status; 434 435 goto end; 436 } 437 438 /* prepare the output buffer */ 439 client = &data->out_client_properties; 440 client->max_msg_length = me_cl->props.max_msg_length; 441 client->protocol_version = me_cl->props.protocol_version; 442 dev_dbg(dev->dev, "Can connect?\n"); 443 444 rets = mei_cl_connect(cl, file); 445 446 end: 447 mei_me_cl_put(me_cl); 448 return rets; 449 } 450 451 /** 452 * mei_ioctl - the IOCTL function 453 * 454 * @file: pointer to file structure 455 * @cmd: ioctl command 456 * @data: pointer to mei message structure 457 * 458 * Return: 0 on success , <0 on error 459 */ 460 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data) 461 { 462 struct mei_device *dev; 463 struct mei_cl *cl = file->private_data; 464 struct mei_connect_client_data connect_data; 465 int rets; 466 467 468 if (WARN_ON(!cl || !cl->dev)) 469 return -ENODEV; 470 471 dev = cl->dev; 472 473 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd); 474 475 mutex_lock(&dev->device_lock); 476 if (dev->dev_state != MEI_DEV_ENABLED) { 477 rets = -ENODEV; 478 goto out; 479 } 480 481 switch (cmd) { 482 case IOCTL_MEI_CONNECT_CLIENT: 483 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n"); 484 if (copy_from_user(&connect_data, (char __user *)data, 485 sizeof(struct mei_connect_client_data))) { 486 dev_dbg(dev->dev, "failed to copy data from userland\n"); 487 rets = -EFAULT; 488 goto out; 489 } 490 491 rets = mei_ioctl_connect_client(file, &connect_data); 492 if (rets) 493 goto out; 494 495 /* if all is ok, copying the data back to user. */ 496 if (copy_to_user((char __user *)data, &connect_data, 497 sizeof(struct mei_connect_client_data))) { 498 dev_dbg(dev->dev, "failed to copy data to userland\n"); 499 rets = -EFAULT; 500 goto out; 501 } 502 503 break; 504 505 default: 506 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd); 507 rets = -ENOIOCTLCMD; 508 } 509 510 out: 511 mutex_unlock(&dev->device_lock); 512 return rets; 513 } 514 515 /** 516 * mei_compat_ioctl - the compat IOCTL function 517 * 518 * @file: pointer to file structure 519 * @cmd: ioctl command 520 * @data: pointer to mei message structure 521 * 522 * Return: 0 on success , <0 on error 523 */ 524 #ifdef CONFIG_COMPAT 525 static long mei_compat_ioctl(struct file *file, 526 unsigned int cmd, unsigned long data) 527 { 528 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data)); 529 } 530 #endif 531 532 533 /** 534 * mei_poll - the poll function 535 * 536 * @file: pointer to file structure 537 * @wait: pointer to poll_table structure 538 * 539 * Return: poll mask 540 */ 541 static unsigned int mei_poll(struct file *file, poll_table *wait) 542 { 543 unsigned long req_events = poll_requested_events(wait); 544 struct mei_cl *cl = file->private_data; 545 struct mei_device *dev; 546 unsigned int mask = 0; 547 548 if (WARN_ON(!cl || !cl->dev)) 549 return POLLERR; 550 551 dev = cl->dev; 552 553 mutex_lock(&dev->device_lock); 554 555 556 if (dev->dev_state != MEI_DEV_ENABLED || 557 !mei_cl_is_connected(cl)) { 558 mask = POLLERR; 559 goto out; 560 } 561 562 if (cl == &dev->iamthif_cl) { 563 mask = mei_amthif_poll(dev, file, wait); 564 goto out; 565 } 566 567 if (req_events & (POLLIN | POLLRDNORM)) { 568 poll_wait(file, &cl->rx_wait, wait); 569 570 if (!list_empty(&cl->rd_completed)) 571 mask |= POLLIN | POLLRDNORM; 572 else 573 mei_cl_read_start(cl, 0, file); 574 } 575 576 out: 577 mutex_unlock(&dev->device_lock); 578 return mask; 579 } 580 581 /** 582 * fw_status_show - mei device attribute show method 583 * 584 * @device: device pointer 585 * @attr: attribute pointer 586 * @buf: char out buffer 587 * 588 * Return: number of the bytes printed into buf or error 589 */ 590 static ssize_t fw_status_show(struct device *device, 591 struct device_attribute *attr, char *buf) 592 { 593 struct mei_device *dev = dev_get_drvdata(device); 594 struct mei_fw_status fw_status; 595 int err, i; 596 ssize_t cnt = 0; 597 598 mutex_lock(&dev->device_lock); 599 err = mei_fw_status(dev, &fw_status); 600 mutex_unlock(&dev->device_lock); 601 if (err) { 602 dev_err(device, "read fw_status error = %d\n", err); 603 return err; 604 } 605 606 for (i = 0; i < fw_status.count; i++) 607 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n", 608 fw_status.status[i]); 609 return cnt; 610 } 611 static DEVICE_ATTR_RO(fw_status); 612 613 static struct attribute *mei_attrs[] = { 614 &dev_attr_fw_status.attr, 615 NULL 616 }; 617 ATTRIBUTE_GROUPS(mei); 618 619 /* 620 * file operations structure will be used for mei char device. 621 */ 622 static const struct file_operations mei_fops = { 623 .owner = THIS_MODULE, 624 .read = mei_read, 625 .unlocked_ioctl = mei_ioctl, 626 #ifdef CONFIG_COMPAT 627 .compat_ioctl = mei_compat_ioctl, 628 #endif 629 .open = mei_open, 630 .release = mei_release, 631 .write = mei_write, 632 .poll = mei_poll, 633 .llseek = no_llseek 634 }; 635 636 static struct class *mei_class; 637 static dev_t mei_devt; 638 #define MEI_MAX_DEVS MINORMASK 639 static DEFINE_MUTEX(mei_minor_lock); 640 static DEFINE_IDR(mei_idr); 641 642 /** 643 * mei_minor_get - obtain next free device minor number 644 * 645 * @dev: device pointer 646 * 647 * Return: allocated minor, or -ENOSPC if no free minor left 648 */ 649 static int mei_minor_get(struct mei_device *dev) 650 { 651 int ret; 652 653 mutex_lock(&mei_minor_lock); 654 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL); 655 if (ret >= 0) 656 dev->minor = ret; 657 else if (ret == -ENOSPC) 658 dev_err(dev->dev, "too many mei devices\n"); 659 660 mutex_unlock(&mei_minor_lock); 661 return ret; 662 } 663 664 /** 665 * mei_minor_free - mark device minor number as free 666 * 667 * @dev: device pointer 668 */ 669 static void mei_minor_free(struct mei_device *dev) 670 { 671 mutex_lock(&mei_minor_lock); 672 idr_remove(&mei_idr, dev->minor); 673 mutex_unlock(&mei_minor_lock); 674 } 675 676 int mei_register(struct mei_device *dev, struct device *parent) 677 { 678 struct device *clsdev; /* class device */ 679 int ret, devno; 680 681 ret = mei_minor_get(dev); 682 if (ret < 0) 683 return ret; 684 685 /* Fill in the data structures */ 686 devno = MKDEV(MAJOR(mei_devt), dev->minor); 687 cdev_init(&dev->cdev, &mei_fops); 688 dev->cdev.owner = mei_fops.owner; 689 690 /* Add the device */ 691 ret = cdev_add(&dev->cdev, devno, 1); 692 if (ret) { 693 dev_err(parent, "unable to add device %d:%d\n", 694 MAJOR(mei_devt), dev->minor); 695 goto err_dev_add; 696 } 697 698 clsdev = device_create_with_groups(mei_class, parent, devno, 699 dev, mei_groups, 700 "mei%d", dev->minor); 701 702 if (IS_ERR(clsdev)) { 703 dev_err(parent, "unable to create device %d:%d\n", 704 MAJOR(mei_devt), dev->minor); 705 ret = PTR_ERR(clsdev); 706 goto err_dev_create; 707 } 708 709 ret = mei_dbgfs_register(dev, dev_name(clsdev)); 710 if (ret) { 711 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret); 712 goto err_dev_dbgfs; 713 } 714 715 return 0; 716 717 err_dev_dbgfs: 718 device_destroy(mei_class, devno); 719 err_dev_create: 720 cdev_del(&dev->cdev); 721 err_dev_add: 722 mei_minor_free(dev); 723 return ret; 724 } 725 EXPORT_SYMBOL_GPL(mei_register); 726 727 void mei_deregister(struct mei_device *dev) 728 { 729 int devno; 730 731 devno = dev->cdev.dev; 732 cdev_del(&dev->cdev); 733 734 mei_dbgfs_deregister(dev); 735 736 device_destroy(mei_class, devno); 737 738 mei_minor_free(dev); 739 } 740 EXPORT_SYMBOL_GPL(mei_deregister); 741 742 static int __init mei_init(void) 743 { 744 int ret; 745 746 mei_class = class_create(THIS_MODULE, "mei"); 747 if (IS_ERR(mei_class)) { 748 pr_err("couldn't create class\n"); 749 ret = PTR_ERR(mei_class); 750 goto err; 751 } 752 753 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei"); 754 if (ret < 0) { 755 pr_err("unable to allocate char dev region\n"); 756 goto err_class; 757 } 758 759 ret = mei_cl_bus_init(); 760 if (ret < 0) { 761 pr_err("unable to initialize bus\n"); 762 goto err_chrdev; 763 } 764 765 return 0; 766 767 err_chrdev: 768 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 769 err_class: 770 class_destroy(mei_class); 771 err: 772 return ret; 773 } 774 775 static void __exit mei_exit(void) 776 { 777 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 778 class_destroy(mei_class); 779 mei_cl_bus_exit(); 780 } 781 782 module_init(mei_init); 783 module_exit(mei_exit); 784 785 MODULE_AUTHOR("Intel Corporation"); 786 MODULE_DESCRIPTION("Intel(R) Management Engine Interface"); 787 MODULE_LICENSE("GPL v2"); 788 789